DIFFERENTIAL FEED ADJUSTMENT MECHANISM FOR FEED-OFF-ARM TYPE SEWING MACHINE

摘要

PROBLEM TO BE SOLVED: To provide a differential feed adjustment mechanism for a feed-off-arm type sewing machine which can adjust the amount of movement of a differential feed dog to the amount of movement suitable for sewing a fabric with small elasticity.;SOLUTION: A differential feed adjustment mechanism 58 for a feed-off-arm type sewing machine includes: a crank shaft 21 which is arranged in a cylinder 61 and is orthogonal to a fabric feed direction F; a differential adjustment crank 20 which is fitted through the crank shaft 21 and swings around the crank shaft 21; a long hole 23 formed in the differential adjustment crank 20; and a square piece 35 which is guided within the long hole 23 so that its vertical position is adjustable. In the case of adjusting the position of the square piece 35 to the lowermost side of the long hole 23, the lower limit of the vertical position adjustment range of the square piece 35 is set so that, when the center of the square piece 35 is located at the lowermost side during the swinging of the differential adjustment crank 20, the center of the square piece 35 and the center of the crank shaft 21 are horizontally positioned.;SELECTED DRAWING: Figure 4;COPYRIGHT: (C)2017,JPO&INPIT